-LRB- CNN -RRB- -- Unless you 've been living under a rock , you know to apply sunscreen . There 's lifesaving reason to : About 3.5 million cases of skin cancer will be diagnosed this year .

`` The incidence of skin cancer , including melanoma -- the deadliest kind -- is going up , and wearing sunscreen is one of the best ways to prevent it , '' says Dr. Ronald Moy , a dermatologist and spokesperson for the Skin Cancer Foundation .

Stick with these smart tips -- and check out our product picks -- to make sure you 're as protected as you can possibly be .

Select a sunscreen you love

Finding your sunscreen soul-mate is the key motivating factor for using it regularly , experts agree .

`` If you think your sunscreen is pasty , thick or smelly , you have the wrong kind , '' says Dr. Jeffrey Dover , clinical associate professor of dermatology at Yale University . `` It may make you less likely to put it on , or to reapply when you do . ''

Happily , there are plenty of lightweight , sheer formulas , like Vichy Capital Soleil Foaming lotion SPF 50 -LRB- $ 29 ; vichyusa.com -RRB- and La Roche-Posay Anthelios 60 Ultra Light sunscreen fluid for face SPF 60 with Cell-Ox Shield XL -LRB- $ 30 ; laroche-posay . us -RRB- .

Health.com : Which sunscreen is best for you ?

Remember , SPF 30 is the new 15

As a general rule , SPF 15 blocks 93 % of UVB rays , SPF 30 blocks 97 % and SPF 50 blocks 98 % . Doctors now typically recommend at least SPF 30 -- at least being the key words .

If you have a family history of skin cancer or are vacationing in a tropical spot -LRB- where the sun is especially intense -RRB- , go for 50 or even 70 .

Just keep in mind : No sunscreen provides 100 % protection . So to be safe as possible , you still need to reapply every two hours and after a swim , even if you used the water-resistant kind , says Dr. Joshua Zeichner , director of cosmetic and clinical research in dermatology at Mount Sinai Hospital in New York City .

Try Neutrogena Beach Defense sunscreen spray broad-spectrum SPF 30 -LRB- $ 11 ; at mass retailers -RRB- . FYI , sunscreen becomes less effective about three years after you open the container .

Health.com : Is it a mole ... or skin cancer ?

Check labels for the term broad-spectrum

It means the sunscreen provides protection against both UVA -LRB- wrinkle - and cancer-causing -RRB- and UVB -LRB- burning -RRB- rays . Problem is , that labeling rule only went into effect in December and stores still sell inventory made prior to it , notes Dr. Steven Wang , director of dermatologic surgery and dermatology at Memorial Sloan-Kettering Cancer Center in Basking Ridge , New Jersey .

So if you 're shopping and there 's no broad-spectrum mention , check the ingredients for zinc or avobenzone , the only two that provide top-notch UVA coverage , he says . Coola Mineral Sport broad-spectrum SPF 35 Citrus Mimosa -LRB- $ 36 ; coolasuncare.com -RRB- contains zinc , and L'OrÃ © al Paris Sublime Sun Liquid Silk Sunshield for face broad-spectrum SPF 30 -LRB- $ 10 ; at mass retailers -RRB- has avobenzone .

Health.com : 7 ways you 're aging your skin

Layer it on

Think you apply enough ? Almost no one does . `` Several big studies show that most people rub in only about a fourth of what 's needed to reach the labeled SPF -- it 's faster and easier to put on just a bit , '' notes Dover .

Instead of that old advice to use a shot glass-size dose , all our experts recommend applying two coats . Squeeze a line of lotion down your arms and legs and rub in , then do it again . Ditto for spray formulas : hold the nozzle close to your skin and spray , moving slowly up and down until you see a sheen , then go back over the area .

For your face , apply a pea-size drop to each cheek , your forehead and your chin , then smear in . Repeat !

Health.com : Sun-proof your skin from a to z

Do n't forget your nose

It 's the number one sunburn-spot , dermatologists say . `` People apply sunscreen to their face , but either skip or speed over their nose -- especially if they wear glasses , because they do n't want to take them off , '' Wang says .

Moy adds , `` 80 % of the skin cancers I remove are on the nose . ''

Other commonly missed areas include the feet , hair part , ears and chest , as well as the backs of hands and legs . Use a sunscreen stick to spot-apply ; try Sun Bum Clear Face Stick SPF 30 + -LRB- $ 10 ; trustthebum.com -RRB- or Ocean Potion Dab-On Spot Stick broad-spectrum SPF 50 + -LRB- $ 5 ; at mass retailers -RRB- .

Get antioxidant insurance

Since rays can still get through sunscreen , companies are now including antioxidants such as vitamins C and E and green tea to help mitigate damage .

If you do n't want to bother applying a serum that contains them beneath your moisturizer or sunscreen -LRB- Wang 's first choice -RRB- , try a souped-up SPF pick , like Supergoop Antioxidant-Infused Sunscreen Mist with Vitamin C broad-spectrum SPF 50 -LRB- $ 19 ; supergoop.com -RRB- .

Health.com : Are Sun Spots Permanent ?

Realize that sunscreen is only one part of a sun-smart plan

`` The hierarchy of sun protection should be avoidance first , then seek shade and wear a wide-brim hat and protective clothing , then use sunscreen -- but most people have that sequence backward , '' Wang points out .

Consider hitting the beach or pool in the morning instead of midday -LRB- when sun is strongest -RRB- , and bring an umbrella and a tightly woven long-sleeve shirt .

Know that it 's never too late to start safe habits

So you baked in the sun as a teen with little or no sunscreen . While regular tanning or getting several bad burns when you 're young raises your risk of skin cancer , Moy says , what 's critical is that you put on sunscreen these days .

`` Since skin 's ability to repair itself decreases with age , your risk is even greater if you burn now . ''

Good thing you 're using it !

Copyright Health Magazine 2011

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Wearing sunscreen is one of the best ways to prevent melanoma

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No sunscreen provides 100 % protection so reapply every two hours

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SPF 15 blocks 93 % of UVB rays , SPF 30 blocks 97 % and SPF 50 blocks 98 %

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About 3.5 million cases of skin cancer will be diagnosed this year